256.255—Accumulated deferred investment tax credits.
(a)
This account shall be credited and account 411.5, Investment tax credit, debited with investment tax credits deferred by companies which do not apply such credits as a reduction of the overall income tax expense in the year in which a tax credit is realized. A proportionate amount shall be debited to account 411.5, Investment tax credit, as determined in relation to the average useful life of service company property to which the tax credit relates or such lesser period of time as may be adopted.
(b)
Records shall be maintained identifying the service company property giving rise to the investment tax credits for each year with the weighted-average service life of such properties and any unused balances of such credits. Such records are not necessary unless the tax credits are deferred.